| Hypericum | |
| Hypericum perforatum,the type species of the genus | |
| Hypericum calycinum,an ornamental plant of the genus | |
| Clades | |
|
The genus Hypericum contains approximately 500 species which are divided into 36 sections as described by botanist Norman Robson. This division into distinct sections is largely due to the fact that a genus-wide monograph was performed by Robson in 1977, which allowed for a comprehensive analysis of the genus's taxonomy. A phylogenetic study was more recently completed for the genus, which gave evidence to suggest that the genus Triadenum is a clade within Hypericum and that the genus Thornea is sister to Hypericum. In addition, the study found that about 60% of the sections of Hypericum are monophyletic.
Almost all species of Hypericum are either perennial herbs, shrubs, or small trees, but the genus also contains a small amount of subshrubs and annual herbs. Most of its species contain hypericin or hyperforin and some are used for their healing properties in folk medicine. The species' leaves are always placed opposite, and are normally decussate. Their flowers are generally homostylous, but very few are dimorphically heterostylous. The petals are normally golden yellow or orange, but some are white or cream, and are veined dorsally. They have 4-5 stamen fascicles, 2-5 ovaries, and 2-5 styles. Some species grow capsular fruit which are colored red or blackish.
Hypericum species can be found all over the world in temperate to tropical areas. The genus is most diverse in Turkey (~80 species) and China (~60 species), but can be found across Asia and Europe, in parts of Africa and South America, Australia, and across the United States and southern Canada. Non-native species have also been introduced into various regions of the United States and Argentina. The genus are generally found in dry, desert areas to being in shallow water, and can be found from warm temperate climates to cold temperate climates.
Some Hypericum species are used as ornamental plants because of their large, spreading flowers. These include H. aegypticum, H. androsaemum, H. calycinum, and H. olympicum. In addition, there are a number of hybrids and cultivars that have been developed for use in horticulture. Some notable cultivars are H. × moserianum, H. 'Hidcote', and H. 'Rowallane'. Several species are also used for their medicinal properties, especially their ability to alleviate mild clinical depression, by drawing out the oily extract from the flowers. H. perforatum is the most potent out of all the species, and is the only species cultivated commercially for herbalism and medicine.
| Type species | |||
|---|---|---|---|
| Binomial | The binomial name of the Hypericum species. | ||
| Common Name | The name that the species is commonly called | ||
| Type | The type of plant that the species is described as | ||
| Distribution | The country or region where the species is most densely found | ||
Adenosepalum Spach is divided into four subsections: Adenosepalum, Aethiopica, Caprifolia, and the Huber-Morathii Group. These subsections contain eight, seven, eleven, and five species, respectively, giving the section Adenosepalum a total of thirty-one species. In addition, Adenosepalum contains two Nothospecies: H. × joerstadii and H. pubescens × tomentosum. H. annulatum has three distinct subspecies.
Adenosepalum is made up of primarily perennial herbs, and also includes shrubs and shrublets. Its species grow to be approximately 2.5 meters tall, and are generally deciduous. Species in Adenosepalum are glabrous or have simple hairs, and almost always have dark black glands on their leaves, sepals, and rarely on their petals and stems. Their leaves are placed opposite and have no ventral glands. Their flowers are stellate or homostylous. They have 5 sepals, 5 stamen fascicles, and 5 petals.
| Binomial | Common Name | Type | Distribution | Image | References | |
|---|---|---|---|---|---|---|
| Subsection Adenosepalum | ||||||
| H. annulatumMoris (1827) | Perennial herb | Balkans, Saudi Arabia, East Africa | [1] [2] | |||
| H. athoumBoiss. & Orph. (1867) | Perennial herb | Greece | ||||
| H. atomariumBoiss. (1827) | Perennial herb | Greece, Turkey, Portugal (Naturalized) | ||||
| H. cuisiniiBarbey (1885) | Perennial herb | Europe | [3] | |||
| H. delphicumBoiss. & Heldr. (1854) | Perennial herb | Evvoia and Andros, Greece | ||||
| H. lanuginosumLam. (1797) | Perennial herb | Middle East, Turkey, Cyprus | ||||
| H. montanumL. (1755) | Pale St. John's Wort | Perennial herb | Eurasia and Morocco | |||
| H. reflexumL.f. (1782) | Shrub | Canary Islands | ||||
| Subsection Aethiopica | ||||||
| H. abilianumN.Robson (1980) | Subshrub | Huíla Province, Angola | ||||
| H. aethiopicumThunb. (1800) | Perennial herb | Southern Africa | ||||
| H. afrumLam. (1797) | Perennial herb | Tunisia, Algeria | ||||
| H. conjungensN.Robson (1958) | Shrub/subshrub | Southwest Tanzania to Zambia | ||||
| H. glandulosumAiton (1789) | Malfurada del Monte | Shrub | Canary Islands and Madeira | |||
| H. kiboënseOliv. (1887) | Shrub/Subshrub | Uganda, Kenya and North Tanzania | [4] | |||
| Subsection Caprifolia | ||||||
| H. caprifoliumBoiss. (1838) | Perennial herb | Spain | ||||
| H. coadunatumChr. Sm. (1825) | Subshrub/Perennial herb | Canary Islands | ||||
| H. collenetteaeN.Robson (1993) | Subshrub/Perennial herb | Saudi Arabia | ||||
| H. naudinianumCoss. & Durieu (1855) | Perennial herb | Morocco, Algeria | ||||
| H. psilophytum(Diels) Maire (1935) | Perennial herb | Morocco, Algeria | ||||
| H. pubescensBoiss. (1838) | Perennial herb | Southern Iberia, North Africa | ||||
| H. scrugliiBacch., Brullo & Salmeri (2010) | Perennial herb | Sardinia | [5] | |||
| H. sinaicumHochst. ex Boiss. (1867) | Perennial herb | Egypt, Arabian Peninsula | ||||
| H. somalienseN.Robson (1958) | Perennial herb | Somalia | ||||
| H. tomentosumL. (1753) | Perennial herb | Western Mediterranean | ||||
| Huber-Morathii Group | ||||||
| H. decaisneanumCoss. & Daveau (1889) | Perennial herb | Libya | ||||
| H. formosissimumTakht. (1940) | Perennial herb | Armenia, Azerbaijan, Turkey | ||||
| H. huber-morathiiN.Robson (1967) | Perennial herb | Anatolia, Turkey | ||||
| H. minutumP.H.Davis & Poulter (1954) | Perennial herb | Mediterranean | ||||
| H. sechmeniiOcak & O.Koyuncu (2009) | Perennial herb | Turkey | ||||
Adenotrias (Jaub. & Spach) R. Keller contains three species: H. aciferum, H. aegypticum, and H. russeggeri. Its type species is H. russeggeri. It is not divided into any subsections. H. aegypticum has three subspecies: H. aegypticum aegypticum L., H. aegypticum maroccanum (Pau) N.Robson, and H. aegypticum webbii (Spach) N.Robson.[6]
Adenotrias contains shrubs and shrublets. Its species can grow to be up to 2 meters tall. Its species are glabrous, but have no dark glands. Their leaves are lined and glandular, and are cortex green. Their flowers are almost tubular, and are heterostylous. They have 5 sepals, 5 petals, and 3 stamen fascicles.
| Binomial | Common Name | Type | Distribution | Image | References | |
|---|---|---|---|---|---|---|
| H. aciferum(Greuter) N.Robson (1967) | Shrublet | Crete | ||||
| H. aegypticumL. (1753) | Egyptian St. John's Wort | Shrub/shrublet | North Africa, Greece, Sardinia | [7] [8] [9] [10] | ||
| H. russeggeri(Fenzl) R.Keller | Shrub/shrublet | Turkey, Syria |
Androsaemum (Duhamel) Godron contains four species: H. androsaemum, H. foliosum, H. grandifolium, and H. hircinum. In addition, Androsaemum contains one Nothospecies: H. × inodorum. It is not divided into subsections. Its type species is H. androsaemum. One of its species, H. grandifolium, has five different subspecies. The section's species are often collectively referred to as Tutsan.
Androsaemum contains shrubs that grow to be from 0.3–2 meters tall. Its species are deciduous and glabrous, but have no dark glands. Their leaves are opposite, decussate, free, and are a pale color. Every species has 20 flowers, branching out from 2 separate nodes, which are homostylous. They have 5 sepals, 5 petals, and 5 stamen fascicles.
| Binomial | Common Name | Type | Distribution | Image | References | |
|---|---|---|---|---|---|---|
| H. androsaemumL. (1753) | Sweet-Amber | Shrub | Southern Europe, North Africa | [11] [12] [13] [14] | ||
| H. foliosumAiton (1789) | Azorean St. John's Wort | Shrub | Portugal (The Azores) | |||
| H. grandifoliumChoisy (1821) | Malfurada | Shrub | Madeira and the Canary Islands | [15] [16] [17] | ||
| H. hircinumL. (1753) | Stinking Tutsan | Shrub | France, Iberia, Italy, Middle East, North Africa | [18] [19] |
Arthrophyllum Jaub. & Spach contains five species, and is not divided into any subsections. Its type species is H. rupestre. Arthrophyllum is most closely related to Webbia.[20]
Arthrophyllum contains shrubs that grow to be approximately 0.9 meters tall and are deciduous but never leafless. Species in Arthrophyllum are glabrous, with reddish to dark glands. Their leaves are placed opposite and are either decussate, sessile, free, or perfoliate and have no ventral glands. They are 40-flowered, and their flowers are stellate and homostylous. They have 5 sepals that lack marginal glands. Arthrophyllum's species also have 5 petals and 3 stamen fascicles, each with 20-40 stamens. Their seeds are narrow and cylindrical.[21]
| Binomial | Common Name | Type | Distribution | Image | References | |
|---|---|---|---|---|---|---|
| H. cardiophyllumBoiss. (1867) | Shrub | Turkey, Lebanon and Syria | [22] [23] | |||
| H. nanumPoir. (1814) | Shrub | Lebanon, Syria and Israel | ||||
| H. pamphylicumN.Robson & P.H.Davis (1980) | Shrub | Turkey | ||||
| H. rupestreJaub. & Spach (1842) | Shrub | Turkey | ||||
| H. vacciniifoliumHayek & Siehe (1914) | Shrub | East Cilicia, Southern Turkey |
Ascyreia Choisy contains exactly 50 species and also includes four nothospecies. The section is one of the largest in the genus that is not divided into any subsections. Its type species is H. calycinum. The section is synonymous with Norysca Spach..[24]
Ascyreia is made up of mostly shrubs or shrublets, but also contains a few trees. Its species generally grow to be from 4–5 meters tall. Some of the species are evergreen, but most are deciduous. They are glabrous, and lack dark glands. Their leaves are opposite, decussate, and free. The section's species have anywhere from 1-25 flowers, which are stellate and homostylous. They have five sepals, which are free. They also have five petals and five stamen fascicles, which each have 20-100 stamens. Their seeds are cylindric or ellipsoid, and some are laterally winged.[21]
| Binomial | Common Name | Type | Distribution | Image | References | |
|---|---|---|---|---|---|---|
| H. acmosepalumN.Robson (1970) | Shrub | China | [25] | |||
| H. addingtoniiN.Robson (1985) | Addington's St. John's Wort | Shrub | China | [26] | ||
| H. augustiniiN.Robson (1970) | Augustine's St. John's Wort | Shrub | China | |||
| H. beaniiN.Robson (1970) | Shrub | China | [27] [28] [29] | |||
| H. bellumH.L.Li (1944) | Shrub | China | [30] | |||
| H. calycinumL. (1767) | Great St. John's WortAaron's Beard Rose of Sharon | Shrub | Bulgaria, Turkey | [31] | ||
| H. choisianumWall. ex N.Robson (1973) | Shrub | China, India, Pakistan | [32] | |||
| H. cohaerensN.Robson (1985) | Shrub | China | ||||
| H. cordifoliumChoisy (1824) | Shrub | Nepal | ||||
| H. curvisepalumN.Robson (1985) | Shrub | China | ||||
| H. elatoidesR.Keller (1904) | subshrub | China | ||||
| H. forrestii(Chitt.) N.Robson (1970) | Forest Tutsan | Shrub | China, Burma | [33] | ||
| H. gaitiiHaines (1919) | Shrub | India | [34] | |||
| H. gracilipesStapf ex C.E.C.Fisch. (1940) | Shrub | India, Bangladesh | ||||
| H. griffithiiHook.f. & Thomson ex Dyer (1874) | Shrub | Bhutan, India | [35] [36] | |||
| H. henryiH.Lév. & Vaniot (1908) | Shrub | China, Southeast Asia | ||||
| H. hookerianumWight & Arn. (1834) | Hooker's St. John's Wort | Shrub | East and South Asia | |||
| H. kouytchenseH.Lév. (1904) | Shrub | China | [37] | |||
| H. laceiN.Robson (1985) | Shrub | Myanmar | ||||
| H. lagarocladumN.Robson (1985) | Shrub | China | ||||
| H. lancasteriN.Robson (1985) | Shrub | China | ||||
| H. leschenaultiiChoisy (1824) | Shrub/small tree | Indonesia | [38] | |||
| H. lobbiiN.Robson (1970) | Shrub | India | ||||
| H. longistylumOliv. | China | |||||
| H. maclareniiN.Robson (1985) | Shrub | China | ||||
| H. monogynumL. (1763) | Shrub | China (Southeast), Taiwan | ||||
| H. mysurenseWall. ex Wight & Arn. (1934) | Shrub | India (South), Sri Lanka | ||||
| H. oblongifoliumChoisy (1821) | Pendant St. John's Wort | Shrub | Pakistan, India, Nepal | |||
| H. pachyphyllumCollett & Hemsl. (1890) | Shrub/undershrub | Myanmar | ||||
| H. patulumThunb. (1784) | Goldencup St. John's Wort Yellow Mosqueta | Shrub | China | [39] | ||
| H. podocarpoidesN.Robson (1977) | Shrub | Nepal, India | ||||
| H. prattiiHemsl. (1892) | Shrub | China | ||||
| H. pseudohenryiN.Robson (1970) | Irish Tutsan | Shrub | China | [40] | ||
| H. reptansHook.f. & Thomson ex Dyer (1874) | Shrublet | China, Burma, India, Nepal | ||||
| H. sherriffiiN.Robson & D.G.Long (1983) | Shrub | Bhutan | ||||
| H. siamenseN.Robson (1985) | Shrub | Thailand | ||||
| H. stellatumN.Robson (1970) | Shrub | China | ||||
| H. subsessileN.Robson (1985) | Shrub | China | ||||
| H. tenuicauleHook.f. & Thomson ex Dyer (1874) | Shrub | Bhutan, India, Nepal | ||||
| H. uralumBuch.-Ham. ex D.Don (1823) | Shrub | China, Burma, India | [41] | |||
| H. wardianumN.Robson (2005) | Shrub | China, Burma | ||||
| H. williamsiiN.Robson (1977) | Shrub | Nepal | ||||
| H. wilsoniiN.Robson (1970) | Shrub | China |
Brathys (Mutis ex L.f.) Choisy is the largest section in Hypericum. It is divided into four subsections: Brathys, Phellotes, Spachium, and Styphelioides. Brathys contains 38 species and the type species, H. juniperinum. Phellotes contains 32 species, Spachium contains 14 species, and Styphelioides contains just 2 species. In total, the section contains 86 species.
Brathys contains a wide variety of plants, including small trees, shrubs, shrublets, and herbs. The largest species in the section grow to be 6 meters tall, and are evergreen. Its species are glabrous—though a few have simple hairs—and lack any dark glands. Their stems are either 4 or 6-lined, and are compressed when the plant is young, but later become terete. Their leaves are placed opposite, are decussate and sessile, and have dense marginal glands. All the species have either one flower on the uppermost node of the plant or 2-15 flowers branching from the uppermost node and from lower secondary nodes. The flowers are stellate or sometimes obconic, and are homostylous. The species have 5 petals which are persistent. They have 5 stamen fascicles which contain anywhere from 1-50 stamens each, formed in a tight ring, to give the plants a total of anywhere from 5-250 stamens. The plants have 5 ovaries, 5 sepals, and 3-5 styles.[21]
| Binomial | Common Name | Type | Distribution | Image | References | |
|---|---|---|---|---|---|---|
| Subsection Brathys | ||||||
| H. aciculareKunth (1821) | Shrub | Peru, Ecuador | [42] | |||
| H. andinumGleason (1929) | Shrub/shrublet | Bolivia, Peru | [43] | |||
| H. baccharoidesCuatrec. (1959) | Shrub | Colombia, Venezuela | ||||
| H. bolivaricumN. Robson (1987) | Shrub | Colombia | ||||
| H. bryoidesGleason (1929) | Subshrub | Colombia | ||||
| H. caracasanumWilld. | Shrub/shrublet | Venezuela | ||||
| H. cardonaeCuatrec. | Shrub/shrublet | Costa Rica, Venezuela, Colombia | ||||
| H. cassiopiformeN. Robson | Shrub | Peru | ||||
| H. costaricenseN. Robson | Costa Rica St. John's Wort | Shrub/shrublet | Colombia, Costa Rica | |||
| H. decandrumTurcz. | Shrub/shrublet | Ecuador, Peru | ||||
| H. harlingiiN. Robson | Shrub | Ecuador | ||||
| H. horizontaleN. Robson | Shrublet | Colombia | ||||
| H. jaramilloiN. Robson | Shrub | Costa Rica, Colombia | ||||
| H. juniperinumKunth | Shrub/shrublet | Colombia, Venezuela | ||||
| H. lancifoliumGleason | Shrub | Colombia, Venezuela | ||||
| H. lancioidesCuatrec. | Shrub | Colombia, Ecuador, Venezuela | ||||
| H. llanganaticumN. Robson | Shrub | Ecuador | ||||
| H. magdalenicumN. Robson | Shrub/small tree | Colombia, Venezuela | ||||
| H. magniflorumCuatrec. | Shrub | Colombia, Venezuela | ||||
| H. marahuacanumN. Robson | Shrub | Colombia, Venezuela | ||||
| H. mexicanumL. | Shrub/shrublet | Colombia, Venezuela | ||||
| H. millefoliumUrb. & Ekman | Shrub | Haiti | ||||
| H. parallelumN. Robson | Shrub | Colombia | ||||
| H. pimeleoidesPlanch. & Linden ex Triana & Planch. | Shrub | Colombia | ||||
| H. prietoiN. Robson (1945) | Shrub | Ecuador | ||||
| H. prostratumCuatrec. | Shrub/Shrublet | Colombia | ||||
| H. pycnophyllumUrb. | Shrub | Dominican Republic | ||||
| H. recurvumN. Robson | Shrub | Peru | ||||
| H. ruscoidesCuatrec. | Shrub | Colombia, Ecuador | ||||
| H. selaginellaN. Robson | Shrublet | Colombia | ||||
| H. spruceiN. Robson | Shrub | Ecuador | ||||
| H. strictumKunth | Shrub | Colombia | [44] | |||
| H. struthiolifoliumJuss. | Shrub | Peru | ||||
| H. stuebeliiHieron. | Shrub | South America | ||||
| H. tetrastichumCuatrec. | Shrub/shrublet | Colombia | ||||
| H. valleanumN. Robson | Shrub | Colombia | ||||
| H. wurdackiiN. Robson | Shrub | Peru | ||||
| Subsection Phellotes | ||||||
| H. acostanumSteyerm. ex N. Robson | Shrub | Ecuador | ||||
| H. asplundiiN. Robson | Shrublet | Ecuador | ||||
| H. callacallanumN. Robson | Shrub | Peru | ||||
| H. carinosumR. Keller | Shrub | Colombia, Venezuela | ||||
| H. castellanoiN. Robson | Shrub/shrublet | Colombia, Venezuela | ||||
| H. cuatrecasiiGleason | Shrub | Colombia | ||||
| H. espinaliiN. Robson | Shrub | Colombia | ||||
| H. garciaePierce | Shrub | Colombia, Venezuela | ||||
| H. gladiatumN. Robson | Shrub | Colombia | ||||
| H. goyanesiiCuatrec. | Shrub | Colombia | ||||
| H. hartwegiiBenth. (1843) | Shrub | Ecuador | ||||
| H. humboldtianumSteud. (1840) | Shrub/shrublet | Colombia, Venezuela | ||||
| H. irazuenseKuntze ex N. Robson | Shrub/small tree | Costa Rica, Panama | [45] | |||
| H. laricifoliumJuss. | Shrub/small tree | Colombia, Ecuador, Peru, Venezuela | [46] | |||
| H. loxenseBenth. | Shrub/shrublet | Ecuador, Peru | ||||
| H. lycopodioidesTriana & Planch. | Shrub | Colombia | ||||
| H. maguireiN. Robson | Shrub | Ecuador | ||||
| H. martenseN. Robson | Shrublet | Colombia | ||||
| H. matangenseN. Robson (1990) | Shrub | Ecuador | ||||
| H. myricariifoliumHieron. | Shrub | Colombia | ||||
| H. papillosumN. Robson | Shrub | Colombia | ||||
| H. paramitanumN. Robson | Shrub/small tree | Venezuela | ||||
| H. phellosGleason (1929) | Shrub/small tree | Colombia, Venezuela | ||||
| H. piriaiArechav. | Atlantic St. John's Wort | Shrub/perennial herb | Brazil, Uruguay | |||
| H. quitenseR.Keller | Shrub/shrublet | Ecuador | ||||
| H. radicansN. Robson | Shrublet | Colombia | ||||
| H. roraimenseGleason | Shrub | Venezuela | ||||
| H. sabiniformeTrevis. | Shrub | Colombia | ||||
| H. simonsiiN. Robson | Shrub (?) | Colombia | ||||
| H. stenopetalumTurcz. | Shrub/small tree | Colombia, Venezuela | ||||
| H. thuyoidesKunth | Shrub/small tree | Colombia | ||||
| H. woodianumN. Robson | Shrub | Colombia | ||||
| Subsection Spachium | ||||||
| H. arbusculaStandl. & Steyerm. | Subshrub/shrublet | Mexico, Guatemala | ||||
| H. beamaniiN. Robson | Shrublet | Guatemala | ||||
| H. chamaemyrtusTriana & Planch. | Subshrub | Colombia, Venezuela | ||||
| H. cymobrathysN. Robson | Shrub | Colombia | ||||
| H. dichotomumLam. | Perennial herb | Dominican Republic, Haiti | [47] | |||
| H. diosmoidesGriseb. | Puerto Rico St. John's Wort | Perennial herb | Caribbean | [48] | ||
| H. drummondii(Grev. & Hook.) Torr. & A. Gray | Drummond's St. John's Wort Nits and Lice | Annual herb | [49] [50] [51] [52] | |||
| H. eastwoodianumI.M.Johnst. | Eastwood's St. John's Wort | Subshrub/shrublet | Mexico | [53] | ||
| H. fuertesiiUrb. | Shrublet/perennial herb | Dominican Republic, Haiti | ||||
| H. galinumS.F. Blake | Shrublet | Mexico | ||||
| H. gentianoides(L.) Britton, Sterns & Poggenb. | PineweedOrangegrass | Annual herb | Canada, United States, South America | [54] [55] | ||
| H. gnidioidesSeem. | Subshrub/shrublet | Costa Rica, Honduras, Panama | ||||
| H. peninsulareEastw. | Subshrub/perennial herb | Mexico | ||||
| H. rubritinctumN. Robson | Shrublet | Mexico | N. Robson | |||
| Subsection Styphelioides | ||||||
| H. styphelioidesA.Rich. | Shrub | Cuba | ||||
| H. terrae-firmaeSprague & L.Riley | Shrub/small tree | Belize | ||||
Bupleuroides Stef. contains one species, H. bupleuroides, which shares the name of the section.
H. bupleuroides is a perennial herb that grows to be approximately 75 centimeters tall. The species' stems sprout from branching rhizomes, and are glabrous and lack dark glands. The leaves are placed opposite and are terete and are perfoliate. It has anywhere from 4-25 flowers that branch from 1-5 nodes and are stellate and homostylous and have 5 petals. There are either 3 or 4 stamen fascicles with 20-25 stamens each. The species has 5 sepals, 3 ovaries, and 3 styles.[21]
Campylopus Boiss. contains one species, H. cerastioides, which is also frequently called H. campylopus. This species is widely cultivated for its vibrant flowers. The section is most closely related to Olympia and Oligostema which are its sister taxa.[56]
Hypericum cerastioides is a perennial herb that grows to be 6-25 centimeters tall, and normally grows upright but sometimes grows prostrate along the ground. It can have a few or numerous stems from plant to plant, and is normally unbranched or branched only below the inflorescence. The stems are white and pubescent with 5-35 millimeter long internodes that can be either shorter or longer than the leaves. It is 1-5 flowered with flowers 2-5 centimeters in diameter. The petals are golden yellow without a tint of red and number 2 times the number of sepals in the inflorescence, and there are 60-100 stamens.
Campylosporus (Spach) R. Keller contains ten species from Africa and the Middle East. Its type species is H. lanceolatum.
The section contains primarily shrubs and trees that can be spreading or grow up to twelve meters tall. They are all evergreen and may or may not have dark glands along the branches. Most species have bark which is fissured and scaly. The species have many flowers which are homostylous. They have five sepals, five petals, and five stamen fascicles which each have 20-45 stamens.[21]
| Binomial | Common Name | Type | Distribution | Image | References | |
|---|---|---|---|---|---|---|
| H. balfouriiN.Robson | Shrub/tree | Socotra | ||||
| H. bequaertiiDe Wild. | Shrub/tree | Kenya, Uganda, Zaïre | ||||
| H. gnidiifoliumA.Rich. | Shrub/tree | Ethiopia | ||||
| H. lanceolatumLam. | Shrub/small tree | Comoros, Réunion | ||||
| H. madagascariense(Spach) Steud. | Madagascar St. John's Wort | Shrub | Madagascar | |||
| H. quartinianumA.Rich. | Shrub/tree | Ethiopia, Kenya, Malawi, Mozambique, Sudan, Tanzania, Uganda, Yemen, Zambia, Zaïre | ||||
| H. revolutumVahl | Curry Bush | Shrub/tree | Middle East, Ethiopia, Cameroon | |||
| H. roeperianumSchimp. ex A.Rich. | Large-leaved Curry Bush | Shrub/tree | Limpopo, South Africa | |||
| H. socotranumR.D.Good | Socotra St. John's Wort | Shrub | Socotra | |||
| H. synstylumN.Robson | Shrub | Ethiopia, Somalia |
Concinna N.Robson contains one species, H. concinnum, which is commonly known as Goldwire.
H. concinnum is a perennial herb or infrequently a subshrub that grows up to 45 centimeters tall. Its stems are erect or ascend from taproots and have dark glands, and change from 4-lined to 2-lined as the species grows. The leaves are placed opposite, and are decussate and free, with closed lamina. The species is 17-flowered and the flowers are stellate and homostylous, with five petals each. The species has five stamen fascicles and a total of 40-100 stamens.
Coridium Spach contains six species from with distributions across Europe. Its type species is H. coris.
The species in the section are low dwarf shrubs or perennial herbs that grow up to 60 centimeters tall. The leaves are glabrous or paperlike, with stems that branch from the taproot and that have dark red and black glands. The leaves are three or four-whorled and have one vein. The species have one to many flowers that come from one to six nodes and are stellate and homostylous. They have five sepals, five petals, and three stamen fascicles with a total of 25-60 stamens.
| Binomial | Common Name | Type | Distribution | Image | References | |
|---|---|---|---|---|---|---|
| H. amblyocalyxCoustur. & Gand (1917) | Dwarf shrub | Crete | ||||
| H. asperuloidesCzern. ex Turcz. (1858) | Perennial herb | Russia | ||||
| H. corisL. (1753) | Heath-leaved St. John's Wort | Low shrub | Switzerland and north-western Italy | |||
| H. empetrifoliumWilld. (1803) | Subshrub | Albania, Greece, Crete, East Aegean Islands, Turkey, Libya | ||||
| H. ericoidesL. (1753) | Dwarf shrub | Spain, Tunisia, Morocco | ||||
| H. jovisGreuter (1975) | Dwarf shrub | Crete |
Crossophyllum Spach contains 4 species of perennial herbs. Its type species is H. orientale. The other species in the section are H. adenotrichum, H. aucheri, and H. thasium.
Species in Crossophyllum grow to be around 55 centimeters tall. They are glabrous, and their stems are erect from a rooting base. Their flowers also branch from the base and sometimes from intermediate nodes. The species have anywhere from 1 to 50 flowers which are stellate and homostylous. Their stems are narrow and eglandular and have dark black or amber glands on raised lines. The leaves are placed opposite and are free and decussate. The species have 5 sepals, 5 petals, and 3 or 5 stamen fascicles with 10-20 stamens each.[21]
| Binomial | Common Name | Type | Distribution | Image | References | |
|---|---|---|---|---|---|---|
| H. adenotrichumSpach (1826) | Kantaron | Perennial herb | Turkey | |||
| H. aucheriJaub. & Spach (1842) | Perennial herb | Bulgaria, Greece, Turkey | ||||
| H. orientaleL. (1753) | Perennial herb | Georgia, Turkey, Russia | ||||
| H. thasiumGriesb. (1843) | Perennial herb | Bulgaria, Greece, Turkey |
Drosocarpium Spach contains small perennial herbs that are found around the Mediterranean. H. richeri has 3 subspecies.
The species in the section grow up to 80 centimeters tall and are glabrous (except H. rochelii). Their leaves are placed opposite and are decussate and free. The species have anywhere between one and seventy flowers branching from one to three nodes which are stellate and homostylous. The species has five petals that are persistent after flowering and erect but not twisting, three or four stamen fascicles with a total of thirty to eighty stamens, and three to four styles.[21]
| Binomial | Common Name | Type | Distribution | Image | References |
|---|---|---|---|---|---|
| H. ambiguumElliott (1821) | |||||
| H. barbatumJacq. (1775) | Bearded St. John's Wort | Perennial herb | Austria, Italy, Balkans | ||
| H. bithynicumBoiss. (1849) | Perennial herb | Georgia, Turkey (Northern) | |||
| H. confusumRose (1906) | |||||
| H. montbretiiSpach (1836) | Perennial herb | Balkans, Turkey, Syria, Lebanon, Russia | |||
| H. perfoliatumL. (1767) | Perennial herb | Iberia, North Africa, France, Italy, Greece, Turkey | |||
| H. richeriVill. (1779) | Alpine St. John's Wort | Perennial herb | Balkans, Switzerland (Alps), Spain (Pyrenees) |